From Monomer Sequence to Self-Assembly in Polyelectrolyte Coacervation

Oppositely-charged polyelectrolytes can undergo an associative phase separation known as complex coacervation, forming dense polymer phases that maximize favorable electrostatic interactions. This interaction motif can be harnessed to drive polymer assembly, via the incorporation of opposite charges on pairs of block copolymers. We present a recent theory developed to describe the equilibrium phase behavior of complex coacervation, capable of predicting both the correlated molecular structure of the bulk coacervate phase as well as matching experimental phase diagrams. We incorporate this model into a self-consistent field theory (SCFT) of polyelectrolyte self-assembly to predict phase diagrams, revealing a correspondence between salt concentration in charge-driven assembly and temperature in solvophobicity-driven assembly. We also show the limits of blockiness, mapping out the transition between micro-phase separated and macro-phase separated polymers as a function of the monomer sequence on a polyelectrolyte.